News & Notes
Vol. 21
Summer 2002
Renewable Energy, Kajima-Style

In less than a century, humankind's consumption of energy has been overwhelming. Depleted energy resources and greenhouse effect induced global warming present critical problems for every nation of the world. One international solution in recent years has been the uptake of renewable sources of natural energy.

In this issue, we will look at three areas of new technological development in the environmental engineering area in which Kajima is involved: solar light power, wind power, and fuel cell power generation utilizing bio-gas from organic waste.

Solar Light Power Generation
Solar light power is attracting a growing market around the world as a clean, re-useable source of energy that emits no atmospheric, sound,vibration, or waste product pollutants. As a general engineering firm, Kajima is challenging to develop new systems that will allow wider acceptance of this technology in our society.

In a country like Japan, where only limited land is available, there has been considerable experimentation with the use of construction materials that incorporate solar panels. Since 1993, Kajima has developed a series of solar panels that could be utilized as building panels without distracting from the appearance of a building. Kajima also developed a new simulation system, which helps us design the most efficient solar panel system for a particular building.

Some of our latest projects such as the Sanyo Solar Ark, the NTT DoCoMo Yoyogi Building and the Fuji Zerox Ebina Office show our ability to provide the solar light power system suitable to a building design and surrounding environment.

Solar Ark
As part of a philosophy of contributing to the advent of a clean energy society,
the Sanyo Electric Group has planned
and built the world's largest single solar power generation system, the Solar Ark.
The facility's power generation capability is 630 kW.

Wind-Generated Power
Wind farms are particularly popular in Europe and the United States since they are seen to be "light" on the environment, and offer relatively low operating and maintenance costs.

However, these wind farms require locations with optimum wind conditions and stable wind direction. Japan's topography is complex, and wind characteristics are difficult to ascertain. Accordingly, there is a tendency to view Japan as unsuited to build wind farms.

The Iwaya Wind Farm
The Iwaya Wind Farm,
built by Kajima in the Tohoku region of northern Japan.
With a total generation capacity of 32.5 MW,
the wind farm is the nation,s largest.
To overcome this difficulty, Kajima's Research & Development Institute developed a new wind prediction technology, which utilizes the latest numerical wind prediction method drawing on meteorological data from the upper air, and topographical and land use data to determine the best locations in a very short time. Another challenging aspect was how to plan and build a wind farm in Japan. As may be imagined, building tall windmills, which exceed heights of 60 or 70 meters, possibly approaching 100 meters in the difficult mountainous terrain that forms many parts of Japan, can be very challenging. It is also important to design the most efficient power generation and distribution system to lower energy costs.

Kajima is applying its general engineering capability and experience in the fields of civil engineering, construction, mechanical and electrical installations to help its clients determine the best power generation system for the region.

We are also applying many years of experience in regional area development business to propose a series of regional development projects to combine a wind farm project with industrial or commercial facilities, which may be able to utilize clean energy from nearby a wind farm.

Fuel Cell Power Generation-Utilizing Bio-Gas from Organic Waste
Approximately 20 million tons of food waste is generated in Japan each year, and when combined with other organic waste such as livestock excrement, amounts to 280 million tons of organic waste per year. What if we could reduce these wastes and generate power without harming our environment?

located in Kobe City, Japan

The photo at left shows the world's first bio-gas fuel cell power plant, built by Kajima in Kobe, Japan. The facility uses food waste collected from hotels in the Kobe City area, which is treated in a proprietary methane fermentation system dubbed "METAKLES." Hydrogen is reformed from methane gas generated from fermentation of organic waste, and reacted chemically with oxygen to produce electricity. It only leaves a very small amount of waste and water. The system does not incinerate materials to generate power, so it does not require additional fuels and releases no harmful exhaust into our atmosphere.

The facility is capable of generating 2,400 kWh per day, which could be used to run and operate the facility. Excess energy could also power surrounding neighbors and electric vehicles. Work is also underway to develop a practical application to produce compressed natural gas (CNG) from the bio-gas and ultimately use it as fuel for CNG vehicles.

The project has attracted considerable attention from both in and outside Japan, where there is a shared issue with waste disposal. Potentially, the system offers a solution that may solve the waste disposal problem and energy shortage without harming our environment. This could well "kill three birds with one stone."

Kajima has amassed a portfolio of expertise in renewable energies through its diverse research and development and engineering projects. The Company is equipped with unique technology and know-how to undertake everything from feasibility studies to system proposals, design, construction, and maintenance, providing a total solution to satisfy customers'energy requirements.

Vol. 21
Summer 2002
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